package com.chain.BrotherExchange.viewmodel.core;

import android.arch.lifecycle.ViewModelStore;
import android.arch.lifecycle.ViewModelStoreOwner;
import android.support.annotation.MainThread;
import android.support.annotation.NonNull;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;

import static com.chain.BrotherExchange.viewmodel.core.HolderFragment.holderFragmentFor;

public class ViewModelStores {

    private ViewModelStores() {
    }

    /**
     * Returns the {@link ViewModelStore} of the given activity.
     *
     * @param activity an activity whose {@code ViewModelStore} is requested
     * @return a {@code ViewModelStore}
     */
    @NonNull
    @MainThread
    public static ViewModelStore of(@NonNull FragmentActivity activity) {
        if (activity instanceof ViewModelStoreOwner) {
            return ((ViewModelStoreOwner) activity).getViewModelStore();
        }
        return holderFragmentFor(activity).getViewModelStore();
    }

    /**
     * Returns the {@link ViewModelStore} of the given fragment.
     *
     * @param fragment a fragment whose {@code ViewModelStore} is requested
     * @return a {@code ViewModelStore}
     */
    @NonNull
    @MainThread
    public static ViewModelStore of(@NonNull Fragment fragment) {
        if (fragment instanceof ViewModelStoreOwner) {
            return ((ViewModelStoreOwner) fragment).getViewModelStore();
        }
        return holderFragmentFor(fragment).getViewModelStore();
    }

}
